WASHINGTON, U.S. - In his first visit to Washington since last June, North Korea's lead nuclear diplomacy negotiator arrived in the country on Thursday, to hold discussions with U.S. officials.

On Thursday evening, North Korea's hardline former spy chief Kim Yong Chol touched down in Washington, months after visiting the U.S. last year, ahead of a meeting between the U.S. President Donald Trump and the North Korean leader Kim Jong Un in Singapore.

In Washington, Chol was reportedly expected to hold talks with the U.S. Secretary of State Mike Pompeo and could also hold a meeting with the U.S. President Donald Trump.

According to reports, Chol's visit to Washington, was aimed at clearing the way for a second U.S.-North Korea summit.

Sources familiar with the agenda of Chol's visit also stated that the meeting could focus on a possible second summit between Kim Jong Un and Donald Trump.

Reports in the South Korean media claimed that Chol had traveled to Washington via Beijing and was carrying another letter for the U.S. President from the North Korean leader.

Further, South Korea's Yonhap news agency said in a report that speculation was rife that the second U.S.-North Korea summit could be held in Vietnam - for which, Chol would hold discussions with Pompeo on Friday.

Neither Chol, nor Pompeo have commented on a potential meeting or a possible agenda for the North Korean official's visit to the U.S.

However, earlier this month, reports pointed out that there had been a flurry of diplomatic activity after the North Korean leader visited China to mark his birthday and held meetings with the Chinese President Xi Jinping.

While Chol is visiting the U.S., another senior North Korean official is said to be heading to Sweden.

Reports in South Korea noted that the North Korean vice-foreign minister Choe Son Hui is heading to Sweden, where she could meet Washington's special representative for Pyongyang Stephen Biegun.

Meanwhile, a Yonhap report quoted unnamed sources as saying that the North Korean leader is scheduled to travel to the communist-run country for an "official state visit" sometime in February.

Progress in denuclearization talks?

Since Trump's June 2018 meeting with Kim Jong Un in Singapore, little progress has been made on North Korean denuclearisation.

Following the historic meeting between the two leaders, talks have stalled over Washington's demand for a complete nuclear disarmament, while Pyongyang has refused to comply with the unilateral demand to denuke.

Chol's visit to Washington comes nearly two months after Pompeo's planned meeting with the North Korean official to discuss a second summit was postponed in November last year.

Subsequently, Kim Jong Un said in his New Year speech that he was willing to meet Trump at any time.

The North Korean official also arrived in Washington merely hours after Trump unveiled a revamped U.S. missile defense strategy, in which the U.S. President singled out the rogue nuclear nation as an ongoing and extraordinary threat.

Yet, experts believe that Chol's visit is a sign of potential movement in a diplomatic process and could yield an announcement of plans for another summit.